Department of Veterinary Anatomy and Histology, College of Veterinary and Animal Sciences, Mannuthy - 680 651, Kerala, India.
*Part of the Ph D thesis submitted by the first author to Kerala Agricultural University.
Prenatal development of the cranial meninges in goats was studied using 52 foetuses with a Crown Rump Length (CRL) ranging from 1.4cm (24 days of gestation) to 41.5cm (full term). The meninges arose as condensation of the neighbouring mesenchyme. The pia mater started differentiating by 24 days of gestational age and the dura at 40 days. Cartilaginous cranial vault also appeared by 40 days. The arachnoid developed at 48 days of age. The dura was generally thicker in the ventral aspect of brain when compared to the sides and top. Arachnoid, the thinnest of the three, followed the infoldings of the dura. It did not follow the sulci of cerebrum and cerebellum but bridged over them. From the arachnoid, strands of fibres formed a loose reticulum across the subarachnoid space. Pia was highly vascularised and extended deep into the sulci. Depending on the vascularity, thickness of the pia mater varied over different regions and at different ages. In the brainstem and cerebellum, thickness was maximum towards the end of second month. But on the cerebral surface it showed maximum development during fifth month. Pia-arachnoid gave a strong positive reaction for alkaline phosphatase.
